Comparison method of determining foreign matter in wool and other material



P 1947- H. J. WOLLNER COMPARISON METHOD OF DETERMINING FOREIGN MATTER IN WOOL AND OTHER MATERIAL Filed Aug. 18, 1945 5 Sheets-Sheet 1 P 1947. H. J. WOLLNER 2,427,435

' COMPARISON METHOD OF DETERMINING FOREIGN MATTER IN WOOL AND OTHER MATERIAL Filed Aug. 18, 1943 5 Sheets-Sheet 2 Sept. 16, 1947.

H.'J. WOLLNE 2,427,435

COMPARISON METHOD OF DETERMINING FOREIGN MATTER IN WOOL -AND OTHER MATERIAL Filed Aug. 18, 1943 5 Sheets-Sheet s Jmw Patented Sept. 16; 1947 COMPARISON METHOD or DETERMINING FOREIGN MATTER IN wooLnNn OTHER MATERIAL Herbert J. Wollner,-Washington. D. C., assignor, by mesne assignments, to Baird Associates, Inc., Cambridge, Mass., a corporation of Massachnsetts Application August 18,1943, Serial No. 499,095

-3 Claims.

In testing and grading various kinds'of Ina-- terial it is frequently necessary to determine thekind and amount of foreign matter in a mass of material. Typical examples are fibrous ma-' terials such as wool, cotton, .rayon .and other natural and synthetic fibers, as well as crystalline materials of various kinds. For example in grading wool it is necessary to determine the weight of intermixed vegetable material such a spiral burrs, cockle burrs, sand burrs; oats'and ..small fragments and slivers commonly called shives. Inasmuch as this vegetable matter is intermixed through the wool and clings tightly thereto,,it is difflcult to make the aforesaid de- I commonly used comprise the hand-picking method, .thesodium hydroxide method. and the carbonizing method.

In the hand-picking method the operator care termination. The -methods fully searches thewool and removes the. vegetable matter piece by piece. The removed pieces are thoroughly cleaned and then weighed to determine the percentage of vegetable matter.

According to the present invention the material is submerged in'a liquid having substantially the same index of refraction as that Of the material and light is transmitted through the submerged material to display the foreign matter, the material becoming substantially transparent when its index of refraction matches that of the liquid so that the foreign matter is rendered visible for comparison with charts depicting similar foreign matter respectively. While the charts may comprise only one chart for each kind of foreign matter and each chart may show only a single piece or. any desired number of 5 pieces of foreign matter, the charts are prefer ably made in sets each set comprising graduated charts depicting predetermined amounts respec- -tively of a particular kind of foreign matter. By

selecting the chart depicting substantially the amount of foreign matter corresponding to that buried in the mass of material, the amount of foreign matter in the-sample is indicated by the By this method'it may require more than a week to test a sample of 50 grams. Thuswhile this is the most accurate method heretofore known, it is also'the most time consuming.

The sodium hydroxide method ismuchmore rapid but not nearly so' accurate. The wool is dissolved in boiling sodium hydroxide solution and the: vegetable matter is then removedby variable quantity of lignin and other components case of very burry wools.

most widely used in the filtering or centrifugal action. The residue is washed, dried and weighed. Inasmuch as a number of the selected chart. The aforesaid comparison may be made by eye or by means of any suitable electrical device such as a scanning device.

The aforesaid illumination may be from the top bottom or side or from any intermediate angle and it may be eifected with-various kinds of light such as a'monochromatic light, polarized light or ordinary daylight. If the illumination is from the bottom the foreign matter is of course displayed in silhouette.

In the preferred embodiment the invention is further characterized as follows. The aforesaid charts are in the form of transparencies and are viewed with transmitted light of approximately the same intensity and color as that of the light transmitted through the submerged Objects of the present invention are toprovide rial which-is quick and easy to practice, which pact apparatus, and" which is generally superior I to the methods heretofore -used.- J

a method of testing and grading massesof matematerial. The charts arearranged in sets, each set depicting graduated amounts, respectively of one kind of foreign matter and the-different sets depicting different kinds of foreign matter respectively. For example one set mayv depict spiral burrs, another'set cockleburrs, etc. For

matter. For example one set may depict large cockle burrs and another set small cockle burrs.

When using charts in the form of trahsparen cies they may be stacked in sup rposition to simulate the appearance of the various kinds of foreign matter intermixed. In grading wool for example the operator may. first select-the trans-.

- 'parency showing approximately-the same size and number of spiral burrs, then the transparency showing approximately the same size and number of shives, etc.,-placing one transparency over the other until all kinds of foreign matter have been matched, whereupon the appearance of the superposed transparencies simulates the appearance of the submerged material. Instead of viewing the transparencies directly they may be viewed indirectly by projecting them either successively or in superposition on a screen adjacent the sample of submerged material. The graduated transparencies may be numbered so that it is necessary merely to add their numbers to determine the amount of foreign matter in the material being tested. The preferred method of making the transparencies is to photograph samples of submerged material having graduated amounts of foreign matter of different kinds. From the negatives thus obtained positives may be printed on glass or film to form the aforesaid transparencies.

For the purpose of illustration a typical embodiment of apparatus for practicing the invention is shown in the accompanying drawings in which Figs. 1 and 1a. are two charts selected. from a set showing difierent amounts of spiral burrs;

Figs. 2 and 2a are two charts selected from a set showing different amounts of cookie burrs;-

Figs. 3 and 3a are two charts selected from a set showing different amounts of sand burrs;

Figs. 4 and 4a are two charts selected from a set showing different amounts of shives;

Fig. 5 is a plan view of the apparatus; and

Fig. 6 is a cross-section of the apparatus.

The particular embodiment of apparatus for practicing the invention chosen for the purpose of illustration comprises a, container for the material having side walls I, 2, 3 and 4, a bottom 5 and a cover 6 which fits loosely into the container. The bottom and cover are made of transparent material such as glass or plastic and if desired the sides may be made of the same material. The cover is pivotally mounted on brackets I,

' fast to table 8 or other suitable support, the cover having arms 9 connected to a bail l9 which is pivotally connected to the brackets at If). The container is disposed over an opening ll so that light may be transmitted from a suitable source l2 upwardly through the material in the container. The light transmitted through the container should be diffused so that the intensity is approximately the same throughout the entire area; and if the bottom of the container is too transparent to serve this purpose a ground glass may 'be interposed at I3. When using a color filter as mentioned hereinafter it too may be placed against the bottom of the container. By setting the container into a recess in the support as indicated in Fig. 6- the diffusing and color filter plates under the container may be readily changed merely by lifting the container out of the recess.

The means for displaying the aforesaid transparencies preferably comprises a light housing l4 containing a light source IS, the housing having an inclined support for the transparencies and a difiusing screen 16 so that both the container and transparencies may be viewed at right angles from a point a short distance above the container. For best results the light transmitted through the diffusing screen l6 has approximately the same color and intensity as that of the light transmitted through the submerged material. Screen It may also serve as a color filter or a separate color filter plate may be placed over or under the screen. By providing an extended support such as indicated at H a number of transparencies may be stacked in superposition.

To grade a. sample of material the liquid is preferably poured into the container first and then a mass of material of predetermined weight is dropped into the liquid in approximately uniform distribution throughout the horizontal cross-sectional area of the container. The cover 6 is then swung down to the position shown in Figs. 5 and 6 to hold the material near the bottom of the container in a shallow layer. For each kind of foreign matter contained in the material the operator selects from the corresponding set of charts the particular chart displaying approximately the same amount of that particular kind of foreign matter. If his first selection does not match the appearance of the submerged material, with respect to that kind of foreign matter, then he selects another chart from the same set showing more or less of the same kind of foreign matter. After matching one kind of foreign matter the selected chart is preferably though not necessarily left on the support I! over the ground glass I6 while the sample is being matched for each of the other kinds of foreign matter contained therein, each selected chart being left on the support l'l over the previously selected charts. After all of the charts have been selected, the appearance of the stack of superposed charts should simulate that of the submerged sample with respect to all kinds of foreign matter.

While the area of the charts need not be the same as that of the container, it simplifies the procedure to have them equal. The charts are preferably photographed from series of samples in the container itself and then printed full size, each series of samples being carefully prepared with graduated amounts of only one kind of foreign matter.

The index of refraction of wool is usually about 1.555 and a relatively transparent liquid having this index of refraction may be made according to either of the following formulae.

Parts Quartz testing oil B (petroleum oil distillate made by Socony Vacuum Oil Co.) 9 Monochlornaphthalene 1 Kerosene 200 Monochlornaphthalene If the color of the wool or other material differs from that of the liquid the difference should be neutralized by coloring the liquid to match the material or by filtering the viewing light to make it match the color of the liquid; and this applies both in photographing the aforesaid charts from predetermined samples and also in comparing the charts with other samples. And in comparing the charts with samples the color of the light from the chart should be matched with that from the liquid, as for example by filtering the chart light.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

Iclaim:

1. In the art of determinin the amounts of foreign matter of different kinds buried in a mass of non-transparent material, the'method which comprises submerging the material in a liquid having substantially the same index of refraction as that of the material, transmitting light through the submerged material to display the foreign matter, and then comparing the display of foreign matter with sets of graduated charts, each set depicting predetermined amounts respectively of one kind of foreign matter and the difl'erent sets depicting difierent kinds of foreign matter respectively, thereby to determine the charts depicting substantially the amounts of foreign matter of different kinds corresponding to that buried in said mass of material.

2. In the art of determining the amount of foreign matter buried in a mass of non-transparent material, the method which comprises submerging the material in a liquid having substantially the same index of refraction as that of the material, transmitting light through the submerged material to display the foreign matter, and then comparing the display of foreign matter with sets of graduated transparencies, each set depicting predetermined amounts respectively of one kind of foreign matter and the different sets depictin different kinds of foreign matter respectively, the transparencies being displayed with transmitted light of approximately the same intensity as that of the aforesaid light, thereby to determine the transparencies depicting substantially the amounts of foreign matter of'different kinds corresponding to that buried in said mass of material.

3. In the art of determining the amount of foreign matter buried in a mass of non-transparent material with sets of graduated transparencies, each set depicting predetermined amounts, respectively, of one kind of foreign matter and the different sets depicting difierent kinds of foreign matter respectively, the method which comprises submerging the material in a liquid having substantially the same index of refraction as that of the material, transmitting light through the submerged material .to display the foreign mat- 6 ter, visually estimating the amounts of the different kinds of foreign matter in said material, making a trial selection from the sets respectively of transparencies which when superposed should match the appearance of said foreign matter, superposing the selected transparencies and, with transmitted light of approximately the same intensity as that of the aforesaid light, making a comparison of the display of foreign matter with the superposed transparencies to determine whether the selected transparencies when viewed in superposition simulate the appearance of the various kinds of foreign matter intermixed and substituting other transparencies until such simulation is obtained.

HERBERT J. WOLLNER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,313,143 Gerber Mar. 9, 1943 2,264,380 Hawk Dec. 2, 1941 1,766,037 Dawson June 24, 1930 251,721 Lomb et a1 Jan. 3, 1882 FOREIGN PATENTS Number Country Date 592,529 ,7 France May 1, 1925 8,686 Great Britain Series of 1899 OTHER REFERENCES Methods of Determining Gloss" by R. S. Hunter, Bureau of Standards Research Paper RP958; published January 1937: pgs. 35 and 36 and plate opposite pg. 23 cited. (Copy in Division '7, U. S. Patent Office.) 

